Water Heater System Having Venturi Draw System

ABSTRACT

A water heater system comprises a water tank, a burner plenum, a flue, and a dilution air blower system. The dilution air blower system comprises a blower, a dilution air passageway, and a venturi system. Air from the blower is forced through the dilution air passageway and discharged toward the venturi system. When the dilution air blower system is attached to the water heater system, air discharged from the dilution air discharge passage via the blower passes through a converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue and out the venturi system.

CROSS-REFERENCE TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

APPENDIX

Not Applicable.

BACKGROUND OF THE INVENTION

This invention relates generally to water heaters and, more particularly, to water heaters that use dilution air to cool hot gasses from the flue.

SUMMARY OF THE INVENTION

One aspect of the invention is a water heater system comprising a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, a flue, a blower adapted and configured to blow air, a dilution air passageway, and a venturi system. The fuel burner is configured and adapted to combust fuel to produce hot combustion products. The flue has an upstream end and a downstream end. The upstream end of the flue is in fluid communication with the burner plenum. The flue is configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue. The venturi system including a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region. The dilution air passageway has a dilution air intake passage and a dilution air discharge passage. The dilution air passageway is in fluid communication with the blower. The blower and dilution air passageway are adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage. The dilution air passageway is positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system. The water heater system is adapted and configured such that air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system.

Another aspect of the present invention is a dilution air blower system adapted and configured to be used with a water heater system. The water heater system comprises a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, and a flue. The fuel burner is configured and adapted to combust fuel to produce hot combustion products. The flue has an upstream end and a downstream end. The upstream end of the flue is in fluid communication with the burner plenum. The flue is configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue to thereby heat water within the tank. The dilution air blower system comprises a blower adapted and configured to blow air, a dilution air passageway, and a venturi system. The venturi system includes a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region. The dilution air passageway has a dilution air intake passage and a dilution air discharge passage. The dilution air passageway is adapted and configured to be in fluid communication with the blower. The blower and dilution air passageway are adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage. The dilution air passageway is positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system. The venturi system further including a combustion products intake passage upstream of and in fluid communication with the converging region. The combustion products intake passage of the venturi system is adapted and configured to be in fluid communication with the downstream end of the flue of the water heater system. The dilution air blower system is adapted and configured such that when the dilution air blower system is attached to the water heater system air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system.

Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic front sectional view of an embodiment of a water heater system of the present invention having a dilution air blower system.

FIG. 2 is an enlarged schematic front sectional view of the dilution air blower system of the water heater system of FIG. 1.

Reference numerals in the written specification and in the drawing figures indicate corresponding items.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A water heater system embodiment of the present invention is generally indicated by reference numeral 10 in FIGS. 1 and 2. The water heater system 10 comprises a water tank 12, a jacket 14 surrounding the water tank, a burner plenum 16 adjacent the water tank, a fuel burner 18 within the burner plenum, a fuel supply line 20, a flue 22, and a dilution air blower system, generally indicated at 30. The fuel burner 18 is configured and adapted to combust fuel (e.g., natural gas, LP gas, etc.) to produce combustion products. The flue 22 includes a flue baffle 34 for providing a rigorous flow path through the flue. The flue 22 has an upstream end 36 and a downstream end 38. The upstream end 38 of the flue 22 is in fluid communication with the burner plenum 16. The flue 22 is configured for passage of combustion products from the burner plenum 16 through the water tank 12 and toward the downstream end 38 of the flue 22 to heat water within the water tank 12. The water tank 12 includes a water inlet and a water outlet (not shown) for introducing unheated water into the tank and for passage of heated water out of the tank, respectively.

The dilution air blower system 30 comprises a blower 40, a dilution air passageway 42, and a venturi system 50. The blower is adapted and configured to draw in ambient air and force it through the dilution air passageway 42. The venturi system 50 includes a converging region 52, a throat region 54 downstream of the converging region, a diverging region 56 downstream of the converging region, and an exit passage 58 downstream of the converging region. The dilution air passageway 42 has a dilution air intake passage 60 and a dilution air discharge passage 62. The dilution air passageway 42 is adapted and configured to be in fluid communication with the blower 40. The blower 40 and dilution air passageway 42 are adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage 62. The dilution air passageway 42 is positioned relative to the converging region 52 of the venturi system 50 and configured such that air discharged from the dilution air discharge passage 62 is directed downstream toward the converging region of the venturi system. The venturi system 50 further including a combustion products intake passage 64 upstream of and in fluid communication with the converging region 52 of the venturi system. The combustion products intake passage 64 of the venturi system 50 is adapted and configured to be in fluid communication with the downstream end 38 of the flue 22 of the water heater system 10.

The dilution air blower system 30 is adapted and configured such that at least a portion of the venturi system 50 is positioned directly above the flue when the water heater system is operational. The downstream end 38 of the flue 22 is adapted for discharging combustion products generally along a longitudinal flue axis X, i.e., upward as shown in FIG. 2. Preferably, the converging region 52, the throat region 54, the diverging region 56 and the exit passage 58 of the venturi system are all aligned with the longitudinal flue axis X. Preferably, the dilution air passageway 42 is configured to discharge air from the blower 40 out the dilution air discharge passage 62 along the longitudinal flue axis X and upstream of the converging region of the venturi system. The dilution air passageway 42 comprises a conduit having a generally straight lateral portion 66 adapted for directing air from the blower along a path that is generally perpendicular to the longitudinal flue axis X.

The dilution air blower system 30 is adapted and configured such that when the dilution air blower system is attached to the water heater system 10, air discharged from the dilution air discharge passage 62 via the blower 40 passes through the converging region 52, throat region 54, diverging region 56 and exit passage 58 of the venturi system 50 to thereby reduce pressure at the downstream end 38 of the flue 22. The reduction in pressure causes hot combustion products to be drawn downstream (upward as shown in FIGS. 1 and 2) through the flue 22 so that such combustion products pass through the flue baffle 34 and then through the converging region 52, throat region 54, diverging region 56, and exit passage 58 of the venturi system 50. The reduction in pressure also draws ambient air into the burner plenum 16 to improve combustion. Air entering the converging region 52 of the venturi system 50 via the dilution air passageway 42 and combustion products entering the converging region of the venturi system via the flue 22 are discharged together via the exit passage 58 of the venturi system.

The water heater system 10 is configured such that during operation of the water heater system 10, the dilution air passing through the dilution air passageway 48 and into the venturi system 50 is sufficient such that the mix discharged from the exit passage 58 is at a temperature low enough to accommodate a PVC vent pipe 70. In particular, the water heater system 10 is configured such that the air and combustion products discharged from the exit passage 58 of the venturi system 50 have a temperature of less than 175° F. during operation of the water heater. Preferably, the dilution air blower system 30 and the venturi system are adapted and configured such that the air and combustion products discharged from the exit passage 58 of the venturi system 50 have a temperature of less than 160° F. when the ambient air entering the dilution air passageway 48 is at a temperature of about 70° F. and the temperature of the combustion products exiting the downstream end of the flue is at a temperature of about 375° F.

Preferably, the dilution air blower system 30 is configured to cause the blower 30 to force air through the dilution air passageway 42 at a flow rate of between about 25 cubic feet per minute and about 50 cubic feet per minute during operation of the water heater system. Preferably, air is discharged from the dilution air discharge passage 62 of the dilution air passageway 42 at a velocity of between about 150 feet/second to about 220 feet/second. The venturi system 50 is configured to produce a pressure differential of at least 2.5 inches of water between the exit passage 58 of the venturi system and the downstream end 38 of the flue 22 during operation of the water heater system 10, and more preferably at a pressure differential of more than about 2.5 inches of water and less than about 5 inches of water. Preferably, the cross-sectional area of the dilution air discharge passage 62 of the dilution air passageway 42 is less than the cross-sectional area of the throat region 54 of the venturi system 30, and more preferably, the cross-sectional area of the dilution air discharge passage is between about 50% and about 75% of the cross-sectional area of the throat region.

In view of the foregoing, it will be seen that several advantages of the invention are achieved and attained.

As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.

It should also be understood that when introducing elements of the present invention in the claims or in the above description of exemplary embodiments of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed, unless such an order is inherent. 

What is claimed is:
 1. A water heater system comprising a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, a flue, a blower adapted and configured to blow air, a dilution air passageway, and a venturi system, the fuel burner being configured and adapted to combust fuel to produce hot combustion products, the flue having an upstream end and a downstream end, the upstream end of the flue being in fluid communication with the burner plenum, the flue being configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue, the venturi system including a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region, the dilution air passageway having a dilution air intake passage and a dilution air discharge passage, the dilution air passageway being in fluid communication with the blower, the blower and dilution air passageway being adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage, the dilution air passageway being positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system, the water heater system being adapted and configured such that air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system.
 2. A water heater system as set forth in claim 1 wherein the water heater system is configured such that the air and combustion products discharged from the exit passage of the venturi system have a temperature of less than 175° F. during operation of the water heater.
 3. A water heater system as set forth in claim 1 wherein the water heater system is configured to cause the blower to force air through the dilution air passageway at a flow rate of between about 25 cubic feet per minute and about 50 cubic feet per minute during operation of the water heater system.
 4. A water heater system as set forth in claim 3 wherein the water heater system is configured to cause air to be discharged from the dilution air discharge passage of the dilution air passageway at a velocity of between about 150 feet/second to about 220 feet/second.
 5. A water heater system as set forth in claim 3 wherein the venturi system is configured to produce a pressure differential of more than about 2.5 inches of water and less than about 5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system.
 6. A water heater system as set forth in claim 3 wherein the venturi system is configured to produce a pressure differential of at least 2.5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system.
 7. A water heater system as set forth in claim 6 wherein the dilution air discharge passage of the dilution air passageway has a cross-sectional area and the throat region of the venturi system has a cross section area, the cross-sectional area of the dilution air discharge passage being less than the cross-sectional area of the throat region.
 8. A water heater system as set forth in claim 6 wherein the cross-sectional area of the dilution air discharge passage is less than about 75% of the cross-sectional area of the throat region.
 9. A water heater system as set forth in claim 1 wherein the water heater system is adapted and configured such that at least a portion of the venturi system is positioned directly above the flue when the water heater system is operational.
 10. A water heater system as set forth in claim 1 wherein the downstream end of the flue is adapted for discharging combustion products generally along a longitudinal flue axis, and wherein the exit passage of the venturi system is aligned with the longitudinal flue axis.
 11. A water heater system as set forth in claim 10 wherein the dilution air passageway is configured to discharge air from the blower out the dilution air discharge passage along the longitudinal flue axis and upstream of the converging region of the venturi system.
 12. A water heater system as set forth in claim 11 wherein the dilution air passageway comprises a conduit having a generally straight lateral portion adapted for directing air from the blower along a path that is generally perpendicular to the longitudinal flue axis.
 13. A water heater system as set forth in claim 11 wherein the throat region of the venturi system is aligned with the longitudinal flue axis.
 14. A dilution air blower system adapted and configure to be used with a water heater system, the water heater system comprising a water tank, a burner plenum adjacent the water tank, a fuel burner within the burner plenum, and a flue, the fuel burner being configured and adapted to combust fuel to produce hot combustion products, the flue having an upstream end and a downstream end, the upstream end of the flue being in fluid communication with the burner plenum, the flue being configured for passage of combustion products from the burner plenum through the water tank and toward the downstream end of the flue to thereby heat water within the tank, the dilution air blower system comprising: a blower adapted and configured to blow air; a dilution air passageway; a venturi system; the venturi system including a converging region, a throat region downstream of the converging region, a diverging region downstream of the converging region, and an exit passage downstream of the converging region, the dilution air passageway having a dilution air intake passage and a dilution air discharge passage, the dilution air passageway being adapted and configured to be in fluid communication with the blower, the blower and dilution air passageway being adapted and configured such that air from the blower is blown through the dilution air passageway and discharged via the dilution air discharge passage, the dilution air passageway being positioned relative to the converging region of the venturi system and configured such that air discharged from the dilution air discharge passage is directed downstream toward the converging region of the venturi system, the venturi system further including a combustion products intake passage upstream of and in fluid communication with the converging region, the combustion products intake passage of the venturi system being adapted and configured to be in fluid communication with the downstream end of the flue of the water heater system, the dilution air blower system being adapted and configured such that when the dilution air blower system is attached to the water heater system air discharged from the dilution air discharge passage via the blower passes through the converging region, throat region, diverging region and exit passage of the venturi system and draws combustion products through the flue such that such combustion products pass through the converging region, throat region, diverging region, and exit passage of the venturi system, whereby air entering the converging region of the venturi system via the dilution air passageway and combustion products entering the converging region of the venturi system via the flue are discharged together via the exit passage of the venturi system.
 15. A dilution air blower system as set forth in claim 14 wherein the venturi system is configured to produce a pressure differential of more than about 2.5 inches of water and less than about 5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system.
 16. A dilution air blower system as set forth in claim 14 wherein the venturi system is configured to produce a pressure differential of at least 2.5 inches of water between the exit passage of the venturi system and the downstream end of the flue during operation of the water heater system.
 17. A dilution air blower system as set forth in claim 14 wherein the dilution air discharge passage of the dilution air passageway has a cross-sectional area and the throat region of the venturi system has a cross section area, the cross-sectional area of the dilution air discharge passage being less than the cross-sectional area of the throat region.
 18. A dilution air blower system as set forth in claim 14 wherein the cross-sectional area of the dilution air discharge passage is less than about 75% of the cross-sectional area of the throat region.
 19. A dilution air blower system as set forth in claim 14 wherein the water heater system is configured to cause air to be discharged from the dilution air discharge passage of the dilution air passageway at a velocity of between about 150 feet/second to about 220 feet/second. 